Process for activating and stabilizing catalyst compositions

Abstract

A process for the production of catalyst materials stabilized in the active state, comprising activating the catalyst starting materials in a reducing gas atmosphere, impregnating the activated catalysts with the melt of a solid inert to the active catlayst, and solidifying the melt impregnation by cooling. The particulate catalyst starting material is passed under the reaction conditions of the activation stage through a reaction zone filled with the reducing gas atmosphere which is in direct contact with the melt of the impregnating solid; the activated catalyst material is introduced into this melt; subsequently removed therefrom; and the molten solid left to solidify. If desired, the impregnated catalyst material may be mechanically size-reduced.

What is claimed is: 
     
       1. A process for the preparation of an activated catalyst composition comprising the steps of A. contacting a shaped particulate catalyst starting material comprising at least one of Cu, Zn, Cr, or an oxide, hydroxide, carbonate, or basic carbonate thereof with a reducing gas in an activation zone at a temperature in the range of from about 200° C. to about 350° C. to produce an activated particulate catalyst  for the reduction of a fatty acid or ester thereof to the corresponding alcohol;   B. impregnating the activated particulate catalyst in an impregnation zone in the presence of said reducing gas with a melted impregnating solid consisting essentially of a fatty alcohol or fatty alcohol mixtures at a temperature of from about 50° C. to about 120° C., said melted solid being inert to the activated catalyst and having a melting point of at least about 40° C.;   C. separating the impregnated activated particulate catalyst from the melted impregnating solid after substantially complete impregnation of the catalyst; and   D. solidifying the impregnating melted solid present on the catalyst; wherein the activation zone temperature is at least about 80° C. higher than the impregnation zone temperature, and the activated catalyst is at a higher temperature than the melted impregnating solid on contact therewith.     
     
     
       2. A process in accordance with claim 1 wherein the resulting impregnated catalyst is mechanically reduced in size. 
     
     
       3. A process in accordance with claim 1 wherein the activation zone temperature is at least about 120° C. higher than the impregnation zone temperature. 
     
     
       4. A process in accordance with claim 1 wherein in step A. the shaped particulate catalyst starting material is in the form of tablets, extrudates or pellets. 
     
     
       5. A process in accordance with claim 1 wherein in step A. the particulate catalyst starting material is passed through a reducing gas-filled activation zone in the form of a static layer having a thickness no greater than about 10 cm. 
     
     
       6. A process in accordance with claim 5 where said layer thickness is no greater than about 5 cm. 
     
     
       7. A process in accordance with claim 1 wherein step A. is carried out by applying the particulate catalyst starting material in the form of a thin layer to a webform support circulating in a reaction zone filled with a reducing gas at a temperature of from about 200° to about 350° C.; step B. is carried out by continuously allowing the hot activated catalyst to fall into a bath of the melted impregnating solid maintained at a temperature of from about 50° to about 120° C.; step C. is carried out by continuously removing the impregnated catalyst from the bath; and step D. is carried out by continuously introducing the impregnated catalyst into a cooling zone filled with an inert gas and maintaining the impregnated catalyst therein until the impregnating layer has solidified. 
     
     
       8. A process in accordance with claim 7 wherein in step B. the activated catalyst falling into the bath is guided onto a moving support which circulates through the bath, removes the impregnated catalyst in step C., and then carries the impregnated catalyst into the cooling zone in step D. 
     
     
       9. A process in accordance with claim 2 wherein the mechanical reduction of the catalyst is carried out with cooling sufficient to prevent melting of the impregnating solid. 
     
     
       10. A process in accordance with claim 1 wherein the catalyst composition is a hydrogenation catalyst composition. 
     
     
       11. A process in accordance with claim 1 wherein the impregnating solid has a melting point of at least about 45° C. 
     
     
       12. A process in accordance with claim 1 wherein the melted impregnating solid in step B. is identical to either the starting material or the end product with which the resulting catalyst is to be used. 
     
     
       13. A process in accordance with claim 1 wherein in step A. the particulate catalyst starting material has a particle size in the range of from about 0.5 to about 20 mm. 
     
     
       14. A process in accordance with claim 13 wherein said particle size is in the range of from about 2 to about 10 mm. 
     
     
       15. A process in accordance with claim 7 wherein the reaction zone in step A. is open to and in direct contact with the bath of melted impregnating solid in step B. 
     
     
       16. A process in accordance with claim 12 wherein the melted impregnating solid in step B. is a fatty alcohol. 
     
     
       17. The process of claim 1, wherein the catalyst comprises copper in combination with one or more oxides of zinc, aluminum, or chromium. 
     
     
       18. The process of claim 1, wherein the catalyst comprises CuO/ZnO/Al 2  O 3 . 
     
     
       19. A process for the preparation of a stabilized, shaped hydrogenation catalyst for converting a fatty acid or fatty acid ester to the corresponding fatty alcohol comprising (a) shaping a catalyst material adapted to catalyze the reduction of a fatty acid or ester thereof to the corresponding fatty alcohol to a particle size of at least about 0.5 mm;   (b) activating the shaped catalyst material by exposing the catalyst material to a reducing gas at an activation temperature of from about 200° C. to about 350° C. to form an activated shaped catalyst;   (c) impregnating the activated shaped catalyst with a melted impregnating solid consisting essentially of a fatty alcohol or mixture thereof having a melting point of from about 30° C. to about 120° C.;   (d) separating the impregnated activated catalyst from the impregnating melted solid after substantially complete impregnation of the catalyst; and   (e) cooling the impregnated catalyst to solidify the impregnating melted solid to form a stabilized, shaped catalyst; wherein the activation temperature is at least about 80° C. higher than the impregnating temperature and the activated catalyst is at a higher temperature than the melted impregnating solid on contact therewith.   
     
     
       20. The process of claim 19, wherein the catalyst comprises an oxide, hydroxide, or carbonate of copper, a copper-free chromium catalyst, or a copper-containing chromium catalyst. 
     
     
       21. The process of claim 19, wherein the catalyst material is adapted to catalyze the reduction of an unsaturated fatty acid or ester thereof to the corresponding unsaturated fatty alcohol. 
     
     
       22. The process of claim 19, wherein the catalyst material is adapted to catalyze the reduction of a methylester of an unsaturated fatty acid to the corresponding unsaturated fatty alcohol. 
     
     
       23. The process of claim 19, wherein the impregnating solid is a tallow alcohol fatty alcohol mixture. 
     
     
       24. The process of claim 22, wherein the catalyst material is a copper-free chromium catalyst. 
     
     
       25. The process of claim 19, wherein the impregnating melted solid has a melting point of at least about 40° C. 
     
     
       26. The process of claim 19, wherein the activation temperature is at least about 120° C. higher than the impregnating temperature. 
     
     
       27. The process of claim 19, wherein the average particle size of the shaped catalyst is from about 2 to 10 mm. 
     
     
       28. The process of claim 19, wherein the average particle size of the shaped catalyst is from about 3 to 8 mm.